The proposed research has two major goals. First, an experimental component will examine whether mother-infant dyads (3 1/2 month-old infants) display improved co-regulation (continuous mutual coordination) in face-to-face interactions across three conditions that increase the amount of physical contact, i.e., no touch, touch only, and holding. Second, a longitudinal component will examine whether co-regulation at 3 1/2 months predicts infant emotion regulation and mother-infant relationship quality at 8 1/2 months. Several features areincluded to bolster knowledge about ongoing processes in the dyad such as naturalistic home visits, bi-weekly infant diaries (assessing variables such as time spent in physical contact, fussiness, and time spent with other caregivers), and measures of maternal stress, social support, and satisfaction with parenting. This work could have implications for the understanding of key processes in early socioemotional development. The experimental component assesses whether physical contact serves not just as a regulator of infant distress, but as a promoter of coordination and mutual responsivity between mothers and infants. The longitudinal component provides an examination of the developmental progression from initially mutually controlled, to self-directed regulation, as well as an assessment of early co- regulation as a window onto the "attachment-in-the-making" phase - a relatively neglected period of relationship formation in the empirical attachment literature since the advent of measures that are not valid until a theoretically stable attachment representation exists.